Boring-bar



I L. R. FAUGHT."

BRING BAB-J.

l Y Patented Deo. 4,1883.

` F|G.a.

Unirse STATES FAT-ENT @reifen l LUTHER R. .FAUGH'L OF PHILADELPHIA, PENNSYLVANIA.

BomNG-BAR. i.

SPECIFICATION forming part of Letters Patent No. 289,522, dated Decemberv 4, 1883.-

` Application filedV July, 21, 1883. (No model.)

.To4 all wle/0m ,it may concern,.-

Beit known that I, `LUTHER R. FAUGHT, of the city and` county` of Philadelphia, inthe State of Pennsylvania, have invented certain new and `useful Improvements in Boring-Bars, of which improvements the following is a specification. t l

Mypresent invention is an improvement upon those for which Letters Patent ofthe United States Nos. 241,481 and 253,523 were granted and issued unto me under` dates of May 17, 1881, and February 14, 1882, respectively; and its objects are to further simplify and reduce the cost of construction of the parts, and to facilitate the manipulation thereof in making such changes as may be from time to H time required in boring operations.

To these ends `my improvements consist in certain novel devices and combinations embracing a boring-bar having two transverse slots at right angles one with the other, two centrally-recessed cutters tting in the slots of said bar, one of said cutters havinga central rib or nipple adapted to bear against the other cutter, a flat set-block fitting in one of the recesses of the boring-bar and serving to hold the cutters in position a clamping-screw, by

" y which the sen-block is forceaagainst minera to the surface of the adjacent cutter, and a packed gland or bushing surrounding the clamping-screw, and serving to prevent the access of borings or other foreign matter to its threads. The improvements claimed are hereinafter more fully set forth.

In the accompanying drawings, Figures l 4and 2 are vertical longitudinal central sections at rightangles one with the other, respectively, through the lower portion of a boringbar embodying my invention; Fig. 3, a view in elevation of the lower end of the boring-bar, and Fig. 4 a transverse section through the same at the line QQ a: of Fig. 1.

In the practice of my invention the boringbar A accords, substantially, withthat of my Letters Patent No. 241,481 aforesaid, in the particular of having adjacent to its lower end two transverse or diametric slots at right angles oneto the other, the width of said slots being sufficient to admit easily the boringtools or cutters, and their depth being greater than the depth of said cutters, so as to allow of the introduction, clamping, and `removal 241,481-I employ under lmy present invention one clampingscrew only, 2 which acts simultaneously uponboth the cutters, as presently to be described. y,

-The boring-tools or cutters E and F, which are inserted in the slots co and a', respectively, of the boring-bar A, `have suitable;` cuttingedges upon each of their ends, and are each reduced in depth at and adjacent to their centers-the upper cutter, F,by a recess in its lower side, and the lower cutter, E, `by a recess in its upperside, the lower: cutter being likewise beveled or relieved upon each of its lower corners. l Shoulders c f are formed upon the upper sides of the cutters E andF, and bear against Ahardened dies G, fitted in the bar A at each end ofthe upper sides of the slots a and a. A central rib or nipple, e', is formed in the recess of the cutter E, said rib acting as the bearing of the cutter E against the cutter F when in position. The nipple e is formed with curved sides, and the ends of the recess are also curved, so as to avoid sharp corners, which would tend to induce breakage of the cutter in stretching under the hammer, and the nipple may either be reduced in height, after the cutter is hardened, or peaned up with a hammer, as may be required to insure its proper bearing upon the upper cutter, F, without interfering with the bearing of the cutter E on the dies G at the top of the slot a.

The cutters E and F are firmly secured in their adjusted positions in the slots a and a by a clamping-screw, D, which engages a central femalev thread in a bushing, C, the latter having an external thread engaging a corresponding thread inthe lower end of the boring-bar. The upper end of the clamping-screw D, which is not threaded, )rojects through the bushing C into the slot a, and bears against the lower side of a set-block, B, of substantially rectangular form, fitting in said slot and serving to transmit the thrust of the screw D to the cutters. The set-block B is slightly beveled or IOO which must be left in the slot for the preliminary adjustment of the cutters is properly lled, and the loss of time and wear of the clamping-screw, which would otherwise be involved in causing the screw to traverse said space, are avoided, with the further advantage of enabling the pressure of the clamping-screw to be quickly released, as only about a single turn is required for the purpose, after which the set-block and cutters' are free to be rcmoved from the slots. The bushing C, which acts as the nut of the clamping-screw D, has no external thread at and adjacent to its upper end, and the corresponding portion of the recess of the boring-bar within which it fits, which is angular or tapering1 at top, is also without a thread, and serves to receive a packer, c, of fibrous and elastic material, or a metallic ring, which surrounds the unthreaded portion of the screw D, and acts to prevent vthe access of borings or other foreign matter to the threads of said screw. rllhe ypacker c may be compressed to any degree of tightness required upon the screw D by screwing up the bushing C, which is properly squared at bottom for the purpose, and the provision of an adjustable packer, in addition to the protection of the screw-threads, as above stated, enables' the screw to properly accommodate itself to the cutter in the event of any spreading under pressure.

It will be obvious that, if preferred, the bushing C might be extended upward, so as to surround the screw D nearly up to its end, being in such case tantamount to a solid gland, Within which a recess for the reception of packing can be formed.

In operation the cutter F is inserted in the slot a and the cutter E in the slot c. Both cutters are then raised, the set-block B inserted, and the clampingscrew D brought to a tight bearingupon the set-block, by which its thrust is transmitted to the cutter E, and thence to the cutter F, both cutters being thus held firmly and securely in position. The removal of the cutters is effected in a similar manner by a reversalof the procedure.

I claim as my invention and desire to secure by Letters Patent- A 1. The combination, substantially as set forth, of a boring-bar having two diametric slots at right angles 011e to the other, a tool or cutter fitting in each of said slots, said cutters abutting ,one against the other, a set-block fitting in one of said slots and adapted to bear against the cutter thereof, and a clampingscrew bearing upon said set-block.

2. The combination, substantially as set forth, of a boring-bar having two diametric slots at right angles one to the other, two centrally-recessed tools or cutters, one of which is provided with a rib or nipple acting as a bearing upon the other, and a clamping-screw engaging a thread in the boring-bar land. eX- erting its thrust upon one of the cutters.

3. The combination, substantially as set forth, o'f a transverselyslotted boring-bar, a tool or cutter fitting in a slot in said bar, a clamping-screw by which said cutter is held in position in the slot, and a ring or packer surrounding said screw at or near its bearing end.

4. The combination, substantially as set forth, of a boring-bar having two diametric slots at right angles one to the other, two tools or cutters tting in said slots and abutting one against the other, a set-block fitting in one of said slots and abutting against the cutter thereof, a clamping-screw bearing on said set-block, an externally-threaded bushing engaging a female thread in the boring-bar and serving as a nut for the clampingscrew, and a ring or packer surrounding the clamping-screw and held in position by the bushing.

, L. lt. FAUGHI.

Vitnesses:

J. SivowDnN BELL, XV. W. DOUGHERTY. 

